The use of such metal cutting tool assemblies has been known for some time, particularly in connection with parting, grooving and face turning operations. The use of such assemblies, particularly with their readily exchangeable or replaceable adaptors, is advantageous when the same tool block is to be used for differing types of cutting inserts, and it is desired to be able to replace these cutting inserts without removing the block from the machine tool to which it is attached. Alternatively, situations may arise where the particular type of cutting operations require the use of differing types of tool blocks, albeit for the same type of cutting insert. In those circumstances, the use of a standard adaptor to which the cutting insert can be clamped is particularly advantageous for it allows for the ready coupling of the cutting insert via the standard adaptor to differing types of tool blocks.
Known adaptors of this kind are formed with a pair of integral jaws which define between them an insert receiving slot for receiving the cutting insert, means being provided for biasing the jaws towards each other so as to clamp the cutting insert in an operative position.